The present invention relates to an outdoor telecommunications cabinet adapted for housing electronic equipment and providing environmental control for such electronic equipment without increasing the xe2x80x9cfootprintxe2x80x9d dimensions of the cabinet.
Modern telecommunications architectures utilize outdoor cabinets to house sensitive electronic equipment installed within a few miles of the subscriber base. These cabinets historically provided protection from the elements for passive cross-connect modules where service could be connected or disconnected, and additional service subscribers were added. As telecommunications and data communications have evolved, the cabinets also began to provide a temperature regulated operating environment for heat-generating electronic equipment, which is generally sized to fit on industry standard racks. The cabinets may be installed on telephone poles or on concrete pads.
One example of a conventional outdoor electrical equipment cabinet is disclosed in U.S. Pat. No. 4,535,386 (Frey, Jr. et al.). This cabinet employs a heat exchanger to dissipate internally generated heat. The heat exchanger exchanges heat between the air in the cabinet and the ambient air outside the cabinet, without allowing the interior and ambient air to mix. In this way, a substantially closed or sealed environment can be maintained within the cabinet, while still allowing for adequate heat dissipation. The heat exchanger is located in the main portion of the cabinet, in proximity to the electronics requiring cooling. However, the presence of the heat exchanger in the cabinet can interfere with the cables used to interconnect the various electronic components, making the routing of these cables somewhat more difficult. Also, since the heat exchanger occupies a significant amount of space, the cabinet must usually be made larger to accommodate it.
U.S. Pat. No. 5,467,250 (Howard et al.) discloses an electrical equipment cabinet that employs a door-mounted heat exchanger so that the heat exchanger does not occupy internal space required for the electrical equipment while maintaining a closed or sealed environment within the cabinet. An arrangement of ducts and vents is used to force interior and exterior air through channels in the heat exchanger using powered fans mounted within the main portion of the cabinet. The mounting of the heat exchanger on or within the door of the cabinet makes more efficient use of the space available within the cabinet.
However, heat exchangers installed in doors also increase the size of the exterior of the cabinet, and may include weighty equipment which adds to the difficulty of opening and closing the door for maintenance work, and may even cause warping of the door over time, rendering it difficult or impossible to properly close and latch. For equipment with high temperature regulation requirements, a door assembly may not be feasible due to the excess weight placed on the door panel. Further, the thickness and weight added to the door by the heat exchanger assembly may require that the base assembly be made larger in order to balance the door/exchanger assembly. In many existing cabinet installations, there is no space for any additional cabinet xe2x80x9cfootprintxe2x80x9d. Heat exchangers in doors require opening the equipment compartment to maintain the exchanger, which may not be desirable. Finally, in cabinets with clamshell doors, there is a center opening, and the individual portions of the door that create the front panel will not be of adequate size to mount the heat exchanger unit.
As telecommunications equipment continues to evolve, new cabinets may be installed close to older passive equipment-containing cabinets to upgrade the type or quality of service available to the local subscriber. In high density housing areas, the cabinets may be installed against building walls and interface with multiple housing units via conduits through the wall. Ongoing challenges include the ability to provide the craft monitoring and addition/disconnection service with full access to both the front and rear of the equipment chassis, while cooling the electronic equipment effectively, interfacing with existing passive equipment and cabinets containing such equipment effectively, interfacing with wiring rooms for large buildings effectively, and accomplishing these tasks while minimizing cabinet size and obtrusiveness in residential and business housing areas and landscaping.
It has now been discovered that new small cabinets designed to handle electronic equipment can be mounted on or near multiple unit users such as apartment buildings or hotels to provide upgraded service without installation in a main wiring room. The cabinet can be installed adjacent to a wall, with minimal intrusiveness or requirement for pad space. The cabinet has an environmental unit installed in a base assembly sub-compartment and does not add to the size of the cabinet footprint, or the weight of the access doors. The base assembly is normally used solely for support or for minor functions, and can now be used to house the environmental control system, i.e., the cooling system without an increase in size of the cabinet.
It has also been discovered that one or two new cabinets can flank an existing passive cross-connect cabinet and be attached to the existing cabinet to house both electronics equipment with a rack and utility electrical interfaces, cooling systems and battery back-up power therefore. This provides the necessary infrastructure for enhanced services such as xDSL on a limited number of subscriber lines within the existing passive cross-connect cabinet.
The invention provides an outdoor telecommunications (telecom) cabinet suitable for pad-mounting or pole-mounting containing one or more xe2x80x9csinglexe2x80x9d electronic equipment racks.
Specifically, the invention provides an outdoor telecommunications cabinet comprising
a) a main electronic compartment including a rear wall panel and two clamshell doors, a floor panel and a cover panel, said compartment including access areas and an equipment storage area, said main compartment adapted to contain heat-generating electrical equipment,
b) at least one rack inside said main electronic compartment for electronic equipment,
c) a base assembly supporting said main electronic compartment, having a width and depth similar to said main electronic compartment capable of being anchored to a base plate or pad,
d) a ventilated sub-compartment in said base assembly containing an environmental cooling system,
e) a pair of clamshell doors, said doors being movable between an open position permitting access to both front and back sides of said electrical equipment and a closed position in which it maintains a substantially closed environment in the electronic compartment,
f) cable entry ports on said rear wall panel,
g) a return air duct assembly mounted to said rear panel to form an enclosed duct vertically traversing the electronic compartment and interfacing with a cutout area on said floor panel for circulating airflow through an enclosed path to said electronic compartment from said sub-compartment,
said environmental control system for effective dissipation of waste heat,
said cabinet being capable of pole-mounting or pad-mounting, or mounting adjacent to a wall to access multiple subscribers.
The invention further provides an outdoor equipment cabinet provided with a single electronic equipment shelf and an access area and a cabinet footprint with dimensions similar to the equipment shelf dimensions plus the access area.
Cabinets of the invention have the environmental control system within a sub-compartment of the base assembly such that access to the electronic components is not affected by the presence of such environmental control system, nor is access to the electronic components necessary to service the environmental control system.
The outdoor electronic equipment cabinet of the invention provides an environmental control system with a totally enclosed duct system.
In one aspect of the invention, an outdoor cabinet for electronic equipment is provided wherein the environmental control system is an air conditioning unit.
In another aspect of the invention, an outdoor cabinet for electronic equipment is provided wherein the environmental control system is a heat exchanger.
The invention further provides a cabinet array, in which the first cabinet is a standard cabinet containing passive telecommunications equipment and a second cabinet is attached to one side panel wherein the second cabinet includes:
a) a main electronic compartment including a rear wall panel and two clamshell doors, a floor panel and a cover panel, said compartment including access areas and an equipment storage area, said main compartment adapted to contain heat-generating electrical equipment,
b) at least one rack inside said main electronic compartment for electronic equipment,
c) a base assembly supporting the main electronic compartment, having dimensions similar to the main electronic compartment capable of being anchored to a base plate or pad,
d) a ventilated sub-compartment in said base assembly containing an environmental cooling system,
e) a pair of clamshell doors, said doors being movable between an open position permitting access to both front and back sides of said electrical equipment and a closed position in which the doors maintain a substantially closed environment in the electronic compartment,
f) cable entry ports on the rear wall panel,
g) a return air duct assembly mounted to the rear panel to form an enclosed duct vertically traversing the electronic compartment and interfacing with a cutout area on the floor panel for circulating airflow through an enclosed path to the electronic compartment from said sub-compartment, the environmental control system providing effective dissipation of waste heat.
Cabinets of the invention may be pad mounted or fitted with adapter brackets and pole mounted. The invention further provides an outdoor cabinet that mounts directly against a building wall to service multiple subscriber buildings.
As used herein, the following terms have these meanings:
1. The terms xe2x80x9cpad-mountedxe2x80x9d, xe2x80x9cpad-mountablexe2x80x9d and the like mean that a cabinet may be attached to a concrete pad which is poured onto the ground.
2. The terms xe2x80x9cpole-mountedxe2x80x9d, xe2x80x9cpole-mountablexe2x80x9d and the like mean that a cabinet may be attached to a telephone pole.
3. The term xe2x80x9ctelecomxe2x80x9d is short for the word telecommunications.
4. The term xe2x80x9cfootprintxe2x80x9d means the area defined by the base of the cabinet.
5. The term xe2x80x9cenvironmental control systemxe2x80x9d means a system for controlling the temperature and/or humidity within the electronic compartment.
6. The term xe2x80x9carrayxe2x80x9d means a set of more than one cabinet that is physically adjacent or attached together.
7. The term xe2x80x9cthe craftxe2x80x9d refers to telecom technical maintenance personnel.